A gym, short for gymnasium ( pl. : gymnasiums or gymnasia), is an indoor venue for exercise and sports. The word is derived from the ancient Greek term "gymnasion". They are commonly found in athletic and fitness centres, and as activity and learning spaces in educational institutions.

A gym is a club, building, or large room, usually containing special equipment, where people go to do physical exercise and get fit.

GYM stands for Gymnasium. A gymnasium or GYM is a covered athletic facility. The word GYM is a short translation of "gymnasium", which is Greek.

The first commercial gym is typically credited to French gymnast and vaudeville-strongman, Hippolyte Triat. He opened his first club in Brussels and then added a second in Paris in the late 1840s. At the end of the 19th century, another gym was established by an entrepreneurial music hall strongman, Eugen Sandow.